Mortality of Talc Miners and Millers From Val Chisone, Northern Italy: An Updated Cohort Study

Our plain-English summary of Mortality of Talc Miners and Millers From Val Chisone, Northern Italy: An Updated Cohort Study, by E. Pira, M. Coggiola, C. Ciocan, et al (Journal of Occupational and Environmental Medicine, 2017).

The study

• Authors: E. Pira, M. Coggiola, C. Ciocan, C. Romano, C. La Vecchia, C. Pelucchi, P. Boffetta
• Journal: Journal of Occupational and Environmental Medicine
• Published: 2017;59(7):659-664
• Cited by: 41 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: The aim of this study was to update the analysis of mortality of a cohort of talc miners and millers in Northern Italy.

Methods: We analyzed the mortality during 1946 to 2013 of 1722 male workers in an asbestos-free talc mine (1166 miners and 556 millers) employed during 1946 to 1995.

Results: The overall standardized mortality ratio (SMR) was 1.24 [95% confidence interval (95% CI) 1.17 to 1.32]; no deaths were observed from pleural cancer; mortality from lung cancer was not increased. Mortality from pneumoconiosis was increased (SMR 26.62; 95% CI 20.71 to 33.69), in particular among miners, and was associated with duration of employment and time since first employment.

Conclusions: We confirmed the lack of association between exposure to asbestos-free talc, lung cancer, and mesothelioma. Increased mortality from pneumoconiosis among miners is attributable to past exposure to silica.

In plain English

This study updated death records for men who worked at a talc mine and mill in Val Chisone, Northern Italy. The authors state that the talc there is free from asbestos. The study covered 1,722 male workers (1,166 miners and 556 millers) employed between 1946 and 1995. Each was followed until death, last contact, age 85 or March 2013, whichever came first; 133 were lost to follow-up. Their deaths were compared with national and regional death rates. Overall, 1,084 deaths occurred against 870.8 expected. There were no pleural cancer deaths (2.0 expected), and the two peritoneal cancer deaths were not mesothelioma. Lung cancer deaths were not increased (75 observed, 72.6 expected). Pneumoconiosis deaths were far higher than expected (69 observed, 2.6 expected), mostly among miners, and rose with longer employment. Oral, pharyngeal and esophageal cancers and cirrhosis were also raised, which the authors considered likely related to heavy alcohol use. The authors concluded there was no association between exposure to the asbestos-free talc studied here and lung cancer or mesothelioma. They attributed the excess deaths from nonmalignant respiratory diseases among miners to past silica exposure.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Updated retrospective cohort mortality study, comparing observed deaths with deaths expected from national and regional rates (standardized mortality ratios)
• Who was studied: 1722 male workers (1166 miners and 556 millers) employed at a talc mine or mill in Val Chisone, Northern Italy, between 1946 and 1995. Follow-up began on January 1, 1946, or at first employment, whichever was later. It ended at last contact, death, the 85th birthday, or March 31, 2013, whichever came first. The original cohort had 1822 subjects; 65 were excluded for invalid data and 35 females were left out.
• Exposure: Talc that the authors state is free from asbestos. Miners were also exposed to silica, mining gases, radon and, since 1991, diesel engine emissions. Millers were exposed to talc and silica.
• Main results:
  • At the end of follow-up, 505 subjects (29.3%) were alive, 1084 (63.0%) were deceased, and 133 (7.7%) were lost to follow-up.
  • Whole cohort: mortality from all causes was higher than expected (1084 observed vs 870.8 expected; SMR 1.24, 95% CI 1.17 to 1.32).
  • Whole cohort: mortality from all cancers was modestly and not significantly higher than expected (SMR 1.04, 95% CI 0.92 to 1.18).
  • Whole cohort: no deaths from pleural cancer (2.0 expected). There were two deaths from peritoneal cancer (1.4 expected), and neither was mesothelioma.
  • Whole cohort: lung cancer deaths were not increased (75 observed vs 72.6 expected; SMR 1.03, 95% CI 0.81 to 1.30).
  • Whole cohort: pneumoconiosis mortality was increased (69 observed vs 2.6 expected; SMR 26.62, 95% CI 20.71 to 33.69).
  • The pneumoconiosis excess was significantly higher in miners than in millers. Miners had 63 deaths (SMR 38.68, 95% CI 29.72 to 49.49); millers had 6 deaths (SMR 6.23, 95% CI 2.29 to 13.58).
  • Pneumoconiosis was the only cause of death associated with duration of employment (test for linear trend p = 0.0005). It also showed a trend with time since first employment (p = 0.0085).
  • Among workers first employed after 1969, there were no deaths from pneumoconiosis (0.3 expected).
  • Whole cohort: significant excess mortality from oral and pharyngeal cancer (SMR 3.83, 95% CI 2.62 to 5.41) and from esophageal cancer (SMR 2.13, 95% CI 1.16 to 3.57). This excess was confined to miners.
  • Whole cohort: increased mortality from cirrhosis (SMR 1.87, 95% CI 1.43 to 2.39). The authors considered the excesses of oral, pharyngeal and esophageal cancer and cirrhosis likely related to heavy alcohol consumption.
• The authors' conclusion: The authors concluded that they confirmed earlier results showing no association between exposure to talc and lung cancer or malignant mesothelioma. The talc in question was the asbestos-free talc of this mine; elsewhere they describe it as talc not contaminated by fibers. They found mortality from nonmalignant respiratory diseases increased in miners and attributed this excess to past exposure to silica.
• Limitations the authors state:
  • No individual exposure data.
  • No information on some potential confounders, such as alcohol drinking.
  • Causes of death were not validated, and there was no information on illness (morbidity).
  • Data on tobacco smoking were limited.
  • For diesel exhaust, the number of miners with sufficiently long latency may not be large.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Talc and vermiculite.

Medical terms in this study, explained in our Lexicon: Talc, Cohort Study, Asbestos-Free Talc, standardized mortality ratio (SMR), confidence interval, Lung Cancer, Pneumoconiosis, Mesothelioma.

Related studies

• Mortality in the cohort of talc miners and millers from Val Chisone, Northern Italy: 74 years of follow-up — C. Ciocan, E. Pira, et al. (2022)
• An update of a mortality study of talc miners and millers in Italy — M. Coggiola, D. Bosio, et al. (2003)
• An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy — G. Piolatto, E. Negri, et al. (1990)
• The 1891-1920 birth cohort of Quebec chrysotile miners and millers: development from 1904 and mortality to 1992 — F.D. Liddell, A.D. McDonald, et al. (1997)
• Mortality among talc miners and millers in New York State — M. Kleinfeld, J. Messite, et al. (1967)
• Mortality from cancer and other causes in the Balangero cohort of chrysotile asbestos miners — E. Pira, C. Pelucchi, et al. (2009)

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